Devices and methods for determining and/or isolating cells such as circulating cancer or fetal cells

Abstract

The present invention generally relates to devices and methods for determining and/or isolating cells. One aspect is generally directed to methods and devices for detecting, identifying, counting, and/or potentially sorting cells of interest in blood or other biological sample. In some embodiments, blood samples (or other biological fluids) may be treated with signaling entities, such as pH-sensitive entities, that change color or otherwise produce a signal in suitable internal environments. For example, certain cells, such as cancer or fetal cells, may have differences in intracellular pH compared to other cells, which can be detected using pH-sensitive entities. In certain embodiments, the cells may be sorted based on such signaling entities; for example, illumination of cells in a suitable machine for sorting cells (e.g., using fluorescent light) may allow determination of the cells, which may also be recovered or isolated for further manipulation in some cases.

What is claimed is: 
     
       1. A method of determining fetal cells within blood from a pregnant human subject, the method comprising:
 exposing blood arising from a pregnant human subject to a pH-sensitive entity, wherein the blood is suspected of containing fetal cells and maternal cells, and wherein the pH-sensitive entity is fluorescent within the fetal cells and not fluorescent within non-cancerous maternal cells; 
 determining the pH-sensitive entity internally within at least some of the cells within the blood by determining fluorescence of the cells; 
 isolating cells based on the determination of the fluorescence of the cells; and 
 confirming that at least some of the isolated cells are fetal cells. 
 
     
     
       2. The method of  claim 1 , further comprising acidifying the blood prior to determining the pH-sensitive entity internally within at least some of the cells within the blood. 
     
     
       3. The method of  claim 2 , wherein acidifying the blood comprises introducing an acid to the blood. 
     
     
       4. The method of  claim 3 , wherein the acid comprises ethylenediaminetetraacetic acid. 
     
     
       5. The method of  claim 2 , wherein acidifying the blood comprises containing the blood in an airtight container. 
     
     
       6. The method of  claim 1 , wherein the pH-sensitive entity comprises one or more of 2′,7′-bis(2-carboxyethyl)-5(6)-carboxyfluorescein tetrakis(acetoxymethyl) ester (BCECF AM), 5(6)-carboxy-2′,7′-dichlorofluorescein, 5(6)-carboxyfluorescein, 5(6)-carboxyfluorescein diacetate, 5(6)-carboxyfluorescein N-hydroxysuccinimide ester, 3,6-diacetoxyphthalonitrile, 6,8-dihydroxy-1,3-pyrenedisulfonic acid disodium salt, Eosin diacetate, or naphthofluorescein. 
     
     
       7. The method of  claim 1 , comprising determining the fluorescence of the cells using a flow cytometer. 
     
     
       8. The method of  claim 1 , further comprising determining the sex of the fetus from which the fetal cells arose. 
     
     
       9. The method of  claim 8 , wherein the fetal cells have an age of less than 8 weeks of gestation. 
     
     
       10. The method of  claim 8 , wherein the fetal cells have an age of less than 5 weeks of gestation. 
     
     
       11. The method of  claim 1 , comprising determining fluorescence of the cells using a fluorescence microscope. 
     
     
       12. The method of  claim 1 , comprising performing genetic analysis on at least some of the isolated cells. 
     
     
       13. The method of  claim 12 , wherein the genetic analysis is used to confirm that at least some of the isolated cells are fetal cells. 
     
     
       14. The method of  claim 12 , wherein the genetic analysis is used to confirm that at least some of the isolated cells are maternal cells. 
     
     
       15. The method of  claim 12 , wherein the genetic analysis is used to determine genetic abnormalities within at least some of the isolated cells. 
     
     
       16. The method of  claim 12 , wherein the genetic analysis is used to determine if at least some of the isolated cells are tumor cells. 
     
     
       17. The method of  claim 1 , comprising sequencing DNA from at least some of the isolated cells. 
     
     
       18. The method of  claim 1 , comprising performing PCR on at least some of the isolated cells. 
     
     
       19. The method of  claim 1 , comprising performing FISH analysis on at least some of the isolated cells. 
     
     
       20. The method of  claim 1 , comprising determining the sex of at least some of the isolated cells.